1. Field of the Invention
The present invention generally relates to a diagnostic device. More particularly, this invention relates to a device for collecting and analyzing a biological fluid.
2. Related Art
Analytical devices for collecting samples and determining the presence or absence and/or quantifying the amount of various analytes in the samples are known in the market. Assays are usually available for abused drugs, pregnancy and fertility testing, and infectious diseases. Most of these existing analytical devices are typically designed and used to analyze urine samples for testing DOA (Drugs Of Abuse) chemicals. Urine has the traditional problem that the sample is usually collected in private, raising security and handling issues, such as sample tampering.
Therefore, it is preferable in some situations to conduct analysis on a saliva sample rather than on a urine sample. When applicable, saliva collection and analysis has several advantages over urine collection analysis. A saliva specimen can be taken at any convenient time, and can be obtained singly or sequentially. Moreover, saliva sampling may be done at any location and can be easily observed, if required.
Devices for collecting and analyzing saliva samples have been developed and introduced commercially. Such devices are generally divided into two types. The first type adopts a configuration wherein a collecting part is separated from the analyzing part. The second type adopts a configuration similar to a mid-stream urine pregnancy test, where samples are collected on a pad and delivered by capillary action to the testing channel in the same device.
However, the first type of devices requires multiple steps and may raise the issue of sample contamination. The second type of devices, which is a major improvement over the first type, is able to perform the sample collection and assay in one step. However, since the second type of devices has to serve both purposes of sample collecting and sample delivering, it requires a soft pad for collecting the sample and a rigid pad for delivering the sample to the testing channel. Further, since the pads cannot be squeezed, it needs a large liquid capacity with minimum retention volume. All these requirements render the designing and selection of padding materials difficult. In addition, since the testing device is attached to the collection pad, it is relatively inconvenient to handle the testing device and very likely to have fluids spilled over the whole device.
Accordingly, it is desirable and advantageous to develop a novel device, which have a separate section to implement sample collection independently and still maintains the functionality of one-step sample assay.